Casino and real estate magnate Donald Trump, who fancies himself a critic of the establishment GOP, has gone to bat for Republican old bull Sen. John McCain, who called fellow Sen. Rand Paul a " wacko bird" for his fillibuster last week that succeeded in getting the White House to reject using drones on U.S. soil.

"I like John McCain. I don't know Rand Paul," said Trump. "I didn't think the filibuster served a purpose."

McCain slapped Paul's filibuster, charging it was silly to think drones would be used to kill Americans. Paul, however, said filibustering the confirmation of CIA Director John Brennan was a necessary stand for libertarian principles.

"This didn't serve a purpose," sneered Trump in an interview on the Andrea Tantaros Show, a syndicated radio program. "They got a letter. The letter said 'we are not going to bomb our own cities,'" said Trump Wednesday. That, he added, "is pretty obvious and I think that's basically what John McCain is saying."

Trump did not repeat McCain's "wacko birds" slam, but said, "It think you should use [the filibuster] for really important things. This, to make a point, he made a point. But it was a point that was already made."